Nuclear Data Sheets for <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:mi mathvariant="normal">A</mml:mi><mml:mo>=</mml:mo><mml:mn>228</mml:mn></mml:math>

Abusaleem, Khalifeh

doi:10.1016/j.nds.2014.01.002

Cited by 36 publications

(13 citation statements)

References 160 publications

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“…but as the half‐lives of all unstable daughters are between 9 and 18 orders of magnitude shorter,

T_{1 / 2} = 14

Gyr is used for all rate calculations. While heat production calculation from the

α

decays is straightforward and requires only the masses of the parent and daughter (equation ), care must be taken with the β – decays of 228 Ra [ Luca , , ], 228 Ac (NuDat v.2.7 β ) [ Abusaleem , ], 212 Pb [ Nichols , , ], 212 Bi [ Nichols , ], and 208 Tl [ Nichols , ], all of which feed several different excited energy levels of their respective daughters. Moreover, 212 Bi has two decay branches: it can decay via the

α

branch (

I = 0.3593

) to 208 Tl or via the β – branch (

I = 0.6407

) to 212 Po [ Nichols , ], and the decay energies of the daughters have to be weighted accordingly; note that direct

α

decays from some excited transitional states of 212 Po to 208 Pb are not treated separately, because they make no difference in the total energy balance.…”

Section: Resultsmentioning

confidence: 99%

Radioactive heat production of six geologically important nuclides

Ruedas

2017

Geochem Geophys Geosyst

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Heat production rates for the geologically important nuclides 26Al, 40K, 60Fe, 232Th, 235U, and 238U are calculated on the basis of recent data on atomic and nuclear properties. The revised data differ by several percent from some older values but indicate that more recent analyses converge toward values with an accuracy sufficient for all common geoscience applications, although some possibilities for improvement still remain, especially in the case of 40K and with regard to the determination of half‐lives. A Python script is provided for calculating heat production (https://github.com/trg818/radheat).

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“…but as the half‐lives of all unstable daughters are between 9 and 18 orders of magnitude shorter,

T_{1 / 2} = 14

Gyr is used for all rate calculations. While heat production calculation from the

α

α

branch (

I = 0.3593

) to 208 Tl or via the β – branch (

I = 0.6407

) to 212 Po [ Nichols , ], and the decay energies of the daughters have to be weighted accordingly; note that direct

α

decays from some excited transitional states of 212 Po to 208 Pb are not treated separately, because they make no difference in the total energy balance.…”

Section: Resultsmentioning

confidence: 99%

Radioactive heat production of six geologically important nuclides

Ruedas

2017

Geochem Geophys Geosyst

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“…Among these, 228 Ra, which is produced by the α-decay of 232 Th, is of special interest due to the low total Q-value (45.8 keV) of its decay. Based on data from the National Nuclear Data Center [16] and the Nuclear Data Sheet [17], 228 Ra decays to 228 Ac via β-particle emission [18]. Since all β-decays from 228 Ra are to excited states of 228 Ac, the β-particle is always accompanied by a γ -ray or a conversion electron as described in the level scheme shown in Fig.…”

Section: Introductionmentioning

confidence: 99%

“…1, which is based in part on measurements and a model-dependent analysis as discussed in [18]. Currently, the lifetimes of the excited states of 228 Ac are unknown [16][17][18]. The odd numbers of protons and odd numbers of neutrons (odd-odd nuclei) suggest the possibility that these are multi-quasiparticle states and deformed nuclei that might result in isomeric states [19].…”

Section: Introductionmentioning

confidence: 99%

Identification of new isomers in $$^{228}$$Ac: impact on dark matter searches

et al. 2021

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We report the identification of metastable isomeric states of $$^{228}$$ 228 Ac at 6.28 keV, 6.67 keV and 20.19 keV, with lifetimes of an order of 100 ns. These states are produced by the $$\beta $$ β -decay of $$^{228}$$ 228 Ra, a component of the $$^{232}$$ 232 Th decay chain, with $$\beta $$ β Q-values of 39.52 keV, 39.13 keV and 25.61 keV, respectively. Due to the low Q-value of $$^{228}$$ 228 Ra as well as the relative abundance of $$^{232}$$ 232 Th and their progeny in low background experiments, these observations potentially impact the low-energy background modeling of dark matter search experiments.

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“…Furthermore, 228 Ra, which is produced by the α-decay of 232 Th, is of special interest due to the low total Q-value (45.8 keV) of its decay. Based on data from the National Nuclear Data Center [17] and the Nuclear Data Sheet [18], 228 Ra decays to 228 Ac via β-particle emission [19]. Since all β-decays from 228 Ra are to excited states of 228 Ac, the β-particle is always accompanied by a γ-ray as described in Fig.…”

mentioning

confidence: 99%

Identification of new isomers in $^{228}$Ac : Impact on dark matter searches

Kim,

Adhikari,

de Souza

et al. 2021

Preprint

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We report the discovery of two metastable isomeric states of 228 Ac at 6.28 keV and 20.19 keV, with lifetimes of 299±11 ns and 115±25 ns, respectively. These states are produced by the β-decay of 228 Ra, a component of the 232 Th decay chain, with β Q-values of 39.52 keV and 25.61 keV, respectively. Due to its low Q-value as well as the relative abundance of 232 Th and their progeny in low background experiments, these observations potentially impact the low-energy background modeling of dark matter search experiments.

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Nuclear Data Sheets for A=228

Cited by 36 publications

References 160 publications

Radioactive heat production of six geologically important nuclides

Radioactive heat production of six geologically important nuclides

Identification of new isomers in $$^{228}$$Ac: impact on dark matter searches

Identification of new isomers in $^{228}$Ac : Impact on dark matter searches

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